Fluid injector pump



1964 v. M. JEMISON ETAL 3,120,811

FLUID INJECTOR PUMP 2 Sheets-Sheet 1 Filed Jan. 29, 1962 INVENTOR. VOLNEY M. JEMISON 8| DON H. YOUNG ATT Feb. 11,1964

V. M. JEMISON ETAL FLUID INJECTOR PUMP Filed Jan. 29, 1962 2 Sheets-Sheet 2 INVENTOR. VOLNEY M. JEM/SON a DON H. YOUNG BY 2 5 i a g 2 ATTORNEY United States Patent F 3,120,811 FLUID ENEEtITGR PUMP Volney M. Jamison and Don H. Young, Phoenix, Ariz., assignors to Thunderbird Engineering Co., Phoenix, Ariz., a corporation of Arizona Filed .l'an, 29, 1962, Ser. No. 172,943 12 Claims. (Cl. 103-38) Our invention relates to fluid pumps and is a continuation-in-part of our prior application Serial No. 164,455, filed January 5, 1962, now abandoned. It relates more in particular to a relatively small, highly accurate pump utilized to inject relatively small quantities of fluid into a treating medium such, for example, as the water utilized for commercial dishwashers.

Frequently pumps of the type to which the present invention relates are controlled by automatic electronic sensing devices which determine the amount of a constituent required in a given medium and feed this information to a control, which in turn controls actuation of the pump to meet the indicated need. it is not essential, of course, that pumps of the present type be utilized in this manner.

The principal object of the present invention is the provision of a fluid injector pump of the general type identified hereinabove.

Another object of the present invention is the provision of a fluid injector pump which has very accurate and foolproof control of the amount of discharge at each reciprocation of the pumps piston.

Another obiect is the provision of an injector pump of the type identified which is inexpensive to produce and maintain.

A further object is the provision of a fluid injector pump which may be operated for a long period of time without attention and without repair or maintenance.

Other specific objects and features of the invention will be apparent from the followin detailed description taken with the accompanying drawings, wherein:

FIG. 1 is a perspective view showing approximately full-scale one form of pump made in accordance with the present invention;

FIG. 2 is an exploded perspective view partly fragmentary showing the principal parts of the FIG. 1 pump;

FIG. 3 is an enlarged vertical sectional view taken through the pump cylinder and actuator housing;

FIG. 4 is a view similar to FIG. 3, but showing the parts in a different position in the rotation and reciprocation of the piston;

FIG. 5 is a view similar to FIGS. 3 and 4, but showing the actuator cam for the suction stroke adjusted to provide different lengths of stroke, and

FIGS. 6 and 7 are elevational views of the piston, taken from opposite sides and showing features of the integral cam surfaces on the piston.

Referring now to the drawings, the numeral 19 (FIG. 2) indicates the pump housing and frame member around which all of the parts of the pump are associated. A suitable electric motor indicated generally by the reference character 11 has a gear train indicated generally by the reference character 12 rotating a driven shaft 13 at a predetermined usually relatively slow rate of speed, although, of course, the rate of speed may be modified within relatively wide range to accommodate dhferent types of systems.

A projection indicated generally by the reference character 16 from one face of the pump housing and frame member 1% forms a cylinder 17 for a piston indicated generally by the reference character 18, and an actuator housing indicated generally by the reference character 19. An inlet port 23 and outlet port 24 are generally oppositely placed to each other, and they provide means for delivering fluid to the cylinder through a tube 25 where it is withdrawn from a suitable source by suction, and delivermg it under pressure through a tube to a suitable point of u se, such for example, as by incorporation into a flowing l1qu1d being used for make-up for a suitable purpose, such, for example, as water for commercial dish-washing and rinsing equipment.

The piston 18 is supported in the cylinder 17 for both rotary and reciprocatory motion longitudinally of its axis. It has a sliding splined connection with drive shaft 13 from the motor 11. The piston has a driving head 27 at one end and a pumping head 28 at the opposite end with a narrow portion 29 in between the two heads. In the specific form shown the head 27 carries an end slot 31 into which a single spline 32 extends in driving relation. The proportion of the spline 32 is such that engagement with the piston will be maintained when the piston is reciprocating at its maximum controlled amplitude in a manner which will be described.

A pair of spaced cams is provided between the two heads of the piston 13 so that by engaging these two cams with suitable actuating devices the piston can be caused to reciprocate as it rotates. In the preferred form of device as shown one cam 33 is provided on the shoulder between the driving head 27 and the narrowed portion 29 of the piston. This cam is so shaped that it forces the piston in a suction stroke away from the cylinder head during one half a complete rotation of the piston. A similar cam 3d is formed on the shoulder between the pumping head 28 and the narrowed portion 29, and it is substantially opposite to the cam 33 in configuration so that on that half-stroke following the raising of the piston in a suction stroke the piston will be caused to return on a pressure or compression stroke to almost substantially bottom against the head gasket 15.

Looking for the moment to FIGS. 3 and 4, we provide a pair of piston actuators 36 and 37, one such actuator 36 in the form of a ball actuator functioning to raise the piston on its suction stroke and a similar ball actuator 37 functioning to return the piston on the compression stroke. In each instance, of course, the actuators 36 and 37 engage against the caniming surfaces of the cams 33 and 34 respectively, with which the ball actuators are in engagement during normal operation. As will be described, the ball actuator 36 is adjustable to control the amplitude of the suction stroke of the piston, but the ball actuator 37 is fixed and always returns to the piston to fully actuated forward compression position. In this manner the amplitude of the pistons reciprocation can be controlled while still always obtaining a positive compression stroke. Full control is thus obtained over the amount of fluid discharged at each reciprocation of the pumps piston.

The ball actuator 37 is supported on a rigid pin 38 held in a hole or a port 39 (see FIG. 2) and held in position by a locking screw 41. The pin 38 has a generally semispherical recess at its forward end within which the ball is rotatably supported. Thus the ball can roll in the end recess in the pin 33 as the piston rotates, wear being reduced to a minimum by this arrangement.

The position of the ball actuator 36 is controlled by an actuating cam member 43 (see FIGS. 2 through 5 inclusive). The cam member 43 has a shank 44 journalled in a support 46 held in the actuator housing by a set screw 47. A cam head 48 with a spiral recessed cam 49 is integral with the shank 44. The spiral recessed cam 49 is shaped to receive almost half of the ball actuator 36, as shown particularly in FIGS. 3 through 5, and hold the same in a guide slot 51 which runs parallel to the axis of the piston 18 but disposed in the common side wall of the cylinder 17 and actuator housing 19. The shank 44 extends entirely through the member 46 and has an adjust-' Patented Feb. 11, 19e4 ing arm 52 secured thereto, whereby the vertical position of the ball actuator 36 within the guide slot 51 can be adjusted to control the amplitude of the reciprocation of the piston 18. The arm 52 is secured in position by a set screw 53 and an anchoring screw 54 holds the arm 52 in a position to which it is adjusted along the surface of the pump housing and frame member 10.

While any suitable valving mechanism may be employed to control the inlet and outlet ports through which fluid is alternately taken into the cylinder 17 and discharged therefrom under pressure, we have obtained very good results by means of the specific arrangement of ports and recesses shown in the drawings and particularly in FIG. 2 thereof.

The piston head 28 has an axial opening 56. A radial opening 57 communicates with said axial opening and also with a peripheral recess 58. The ports 23 and 24 on the cylinder 17 have already been described. The several ports and recesses are so arranged that when the pump starts its suction stroke and throughout such suction stroke the recess 53 is in communication with the port 23. During the time that the pump is discharging, however, the recess 58 is in communication with the outlet port 24. The radial dimension of the recess 58 must, therefore, be great enough as the piston is rotating to permit withdrawal of fluid from a source through the inlet 23, and provide a path for discharge of the fluid as the piston moves through the compression part of its stroke.

It will be apparent to those skilled in the art that if the cams 33 and 34 were shaped to provide continuous reciprocation of the piston 18 with no rest period at the ends of the stroke, it would be necessary to extend the recess 58 almost half-way around the circumference of the piston, so that the width of the two ports 23 and 24 plus twice the width of the recess 58 would approximately equal three hundred and sixty degrees of circumference. Unless this were so, there would be a tendency to build up unusually high pressure within the cylinder 17 during the'first part of the pressure stroke until the outlet port opened, and, in the case of a completely uncompressible liquid, failure by leakage could occur. So, also, a partial vacuum would develop during the first part of the suction stroke. This surging is at least inefficient and should be avoided.

While it is within the range of possible design to provide a large recess 58 and suitably dimensioned ports, we find it preferable to provide flat spots 30 and 35 on the cams 33 and 34 at the high portion of each cam, as shown particularly in FIGS. 6 and 7. The low sides of the cams may be shaped to at least partially match these two flat portions but need not be so shaped. Thus the flat portion 35 on cam 34 allows the piston to remain at its lowermost position during the period when the recess 58 is moving from port 24 to port 23. When, now, the cam 33 starts to raise the piston 18, the recess 58 is in partial communication with port 23 and fluid can enter the cylinder. Similarly, at the top of its stroke, the flat portion 30 of cam 33 provides a dwell period while the recess 58 is moving to a position to uncover port 24. When the pressure stroke of the piston starts by the actuator 37 riding on the camming surface of cam 34, the outlet port 24 can receive fluid under pressure and no high pressure surge in the cylinder 17 will develop.

While the dimensioning of the ports may vary, the width of the flat portions 30 and 35, the width of the ports 23 and 24 and the width of recess 58 multiplied by two, and all measured circumferentially, should total about three hundred and sixty degrees for best results.

In producing the pump of the present invention, the motor and pump portion are first assembled as sub-assemblies and thereafter secured together to produce the completed device. It is normally enclosed in a further housing which also contains a source of fluid to be handled by the injector pump and other control mechanism associated with it. There is no particular problem to assembling the parts of the pump itself, except it might be noted that the adjustable actuator ball 36 is preferably dropped down into a position within the guide slot 51 after the piston has been inserted in the cylinder and before the actuator cam 43 has been inserted. By inserting the actuator cam and rotating it simultaneously to pick up the ball 36 within the cam recess 49, the actuator ball 36 may be firmly lodged in the position shown in the drawings, after which assembly of the remaining parts is readily completed.

Looking at the drawings and particularly FIG. 3, the piston is bottomed substantially against the cylinder head gasket 23 having been forced to this position by the actuator 37 operating against the cam 34. It will be noted that at this position the recess 58 on the piston is in communication with the port 24. In FIG. 4 the piston has been raised substantially the maximum by the actuator 36 operating against the surface of cam 33. It may be noted that at this extreme position the inlet port 23 and the re cess 58 are in communication. FIG. 5 shows the piston raised only very slightly on its suction stroke, this relatively small rise being due to the actuator 36 riding on cam 33 and the fact that actuator 36 has been adjusted to a relatively much lower position in the guide slot 51 than it occupies in FIG. 4. Thus the amount of fluid delivered at each reciprocation of the piston may be controlled. For further control, of course, the speed at which the iston rotates may be controlled and this is a matter of controlling the gearing employed with the motor 11. Generally speaking, a single pump is constructed so that with normal actuation by control of the arm 52 all usual or normal requirement conditions can be met.

We have described and shown a specific preferred embodiment of the present invention, but it is obvious that details of construction may be modified and the scope of the invention is, therefore, defined by the claims.

.1. In a fluid injector pump:

(a) means forming a cylinder,

(b) a piston reciprocal-1y and rotatably supported in said cylinder,

(0) said piston having a relatively reduced diameter central section with a fluid pumping head portion at one side thereof and a driving head at the opposite side,

(d) drive means having a sliding connection to said head for rotating said piston,

(e) said piston having one cam on a face of the pumping head facing said reduced diameter portion and a second cam on a face of the driving head facing said reduced diameter portion,

(1) a first actuator engaging said first-mentioned cam to move the piston as it rotates in a longitudinal direction in a pressure stroke, and

(g) a second actuator engaging said second-mentioned cam to move said piston as it rotates in a longitudinal direction in a suction stroke.

2. In a fluid injector pump:

(a) means forming a cylinder,

(b) a piston reciprocally and rotatably supported in said cylinder,

(0) said piston having a relatively reduced diameter central section with a fluid pumping head portion at one side thereof and a driving head at the opposite side,

(d) drive means having a sliding connection to said head for rotating said piston,

(e) said piston having one cam on a face of the pumping head facing said reduced diameter portion and a second cam on a face of the driving head facing said reduced diameter portion,

(f) a first actuator engaging said first-mentioned cam to move the piston as it rotates in a lonigtudinal direction in a pressure stroke,

(g) a second actuator engaging said second-mentioned cam to move said piston as it rotates in a longitudinal direction in a suction stroke, and

(h) means for controlling the position of said second actuator to thus control the amplitude of said suction stroke and thus to control the pumps output at each reciprocation.

3. In a fluid injector pump:

(a) means forming a cylinder,

(b) a piston reciprocally and rotatably supported in said cylinder,

(0) said piston having a relatively reduced diameter central section with a fluid pumping head portion at one side thereof and a driving head at the opposite side,

(d) drive means having a sliding connection to said head for rotating said piston,

(e) said piston having one cam on a face of the pumping head facing said reduced diameter portion and a second cam on a face of the driving head facing said reduced diameter portion,

(f) an actuator housing fixed to said cylinder means,

(g) an actuator guide slot being disposed in a common wall between said cylinder and actuator housing,

(h) a first actuator disposed in said guide slot and engaging said cam on said driving head to move said piston longitudinally on a suction stroke driving one half a piston revolution,

(i) a second actuator engaging said cam on said fluid pumping head of the piston during another half rotation of the piston to move said piston longitudinally on a compression stroke, and

(j) means for rotating said piston.

4. In a fluid injector pump:

(a) means forming a cylinder,

(b) a piston reciprocally and rotatably supported in said cylinder,

(c) said piston having a relatively reduced diameter central section with a fluid pumping head portion at one side thereof and a driving head at the opposite side,

(d) drive means having a sliding connection to said head for rotating said piston,

(e) said piston having one cam on a face of the pumping head facing said reduced diameter portion and a second cam on a face of the driving head facing said reduced diameter portion,

(1) an actuator housing fixed to said cylinder means,

(g) an actuator guide slot being disposed in a common wall between said cylinder and actuator housing,

(It) a first actuator disposed in said guide slot and engaging said cam on said driving head to move said piston longitudinally on a suction stroke driving one half a piston revolution,

(1') a second actuator engaging said cam on said fluid pumping head of the piston during another half rotation of the piston to move said piston longitudinally on a compression stroke,

(1 means for rotating said piston, and

(k) means for controlling the position of said first actuator in said guide slot to control the amplitude of said longitudinal suction movement of said piston.

5. An injector pump as defined in claim 4, wherein:

(a) each of said cams has a flat portion at its high side to minimize surging of pressure within the cylinder.

6. In a fluid injector pump:

(a) means forming a cylinder,

(b) a piston reciprocally and rotatably supported in said cylinder,

(c) said piston having a relatively reduced diameter central section with a fluid pumping head portion at one side thereof and a driving head at the opposite side,

((1) drive means having a sliding connection to said head for rotating said piston,

(e) said piston having one cam on a face of the pumping head facing said reduced diameter portion and a second cam on a face of the driving head facing said reduced diameter portion,

(f) an actuator housing fixed to said cylinder means,

(g) an actuator guide siot being disposed in a common wall between said cylinder and actuator housing,

(It) a first actuator disposed in said guide slot and engaging said cam on said driving head to move said piston longitudinally on a suction stroke driving one half a piston revolution,

(1') a second actuator engaging said cam on said fluid pumping head of the piston during another half rotation of the piston to move said piston longitudinally on a compression stroke,

(i) means for rotating said piston, and

(k) cam means rotatably supported in said actuator housing for controlling the position of said first actuator in said guide slot to control the amplitude of said longitudinal suction stroke movement of said piston.

7. An injector pump as defined in claim 6, wherein:

(a) said actuators are hardened balls,

(b) said second actuator carried in an end recess on a pin support projecting through said actuator housing with its axis generally at right angles to the axis of the piston.

8. In a fluid injector pump:

(a) a pump housing and frame member with a generally circular base and an integral projection from one side forming a pump cylinder and .actuator housing with their axes generally aligned and with circular cross-section cylinder or housing openings extending entirely through said base,

(1;) a cam actuator guide slot being provided in a common wall between the cylinder and actuator housing,

(c) a piston rotatably and reciprocally carried in said pump cylinder,

(:1) said piston having a pumping head at one end, a driving head at the end opposite the pumping head, and a pair of spaced peripheral cams between said heads,

(e) an electric motor with a drive shaft on said base,

(1) a splined connection between said motor drive shaft and driving head of the piston,

(g) a ball actuator in said guide slot engaging one of said piston cams to move the piston longitudinally on a suction stroke during a half rotation,

(11) an actuator adjusting cam member adjustably and rotatably supported in said actuator housing and having a spiralled recessed cam into which said ball actuator engages, whereby to permit longitudinal adjustment of the ball position in said cam to control the amplitude of said suction stroke,

(i) a second ball actuator engaging said second cam on said piston to move the piston during a half rotation longitudinally on a compression stroke,

(j) a pin support for said second ball actuator,

(k) said pin secured in said housing in a position generally at right angles to the piston axis and having an end recess holding said ball cam firmly to cause said compression stroke to have a fixed amplitude, and

(l) valve means admitting fluid to said cylinder on said suction stroke and discharging the same under pres sure during said compression stroke.

9. In a fluid injector pump:

(a) a pump housing and frame member with a generally circular base and an integral projection from one side forming a pump cylinder and actuator housing with their axes generally aligned and with circular cross-section cylinder or housing openings extending entirely through said base,

(b) a cam actuator guide slot being provided in a common wall between the cylinder and actuator housing,

(0) a piston rotatably and reciprocally carried in said pump cylinder,

(d) said piston having a pumping head at one end and a pair of spaced peripheral cams between said heads,

(e) an electric motor with a drive shaft on said base,

(1) a splined connection between said motor drive shaft and driving head of the piston,

(g) laball actuator in said guide slot engaging one of said piston cams to move the piston longitudinally on a suction stroke during a half rotation,

(11) an actuator adjusting cam member adjustably and rotatably supported in said actuator housing and having a spiralled recessed cam into which said ball actuator engages, whereby to permit longitudinal adjustment of the ball position in said cam to control the amplitude of said suction stroke,

(i) a second ball actuator engaging said second cam on said piston to move the piston during a half rotation longitudinally on a compression stroke,

(1') a pin support for said second ball actuator, V

(k) said pin secured in said housing in a position generally at right angles to the piston axis and having Ian end recess holding said ball cam firmly to cause said compression stroke to have a fixed amplitude,

(I) said cylinder having oppositely facing inlet and exhaust ports and said piston pumping head having a single radial port generally aligned with said inlet and exhaust ports,

(m) an axialopening communicating with said radial port and a peripheral recess with which said radial port communicates,

' (u) said ports and recesses being so dimensioned and positioned that said recess is over said inlet port in the cylinder as the piston rotates and reciprocates on its suction stroke to cause fluid to fiow through said radial port and axial opening into the cylinder, and

(0) said recess is over the exhaust port to permit fluid (b) said cams comprising shoulders between said nar- )I'OWjCIOSS-SBClIlOH por'tion', andwherein; i i

(c) said piston opening in; which thepistonfis'supported extends entirelythrough saidcylinder housing and is of uniform cross-section throughout, 1 l

(d said piston, having end threads and'a screw-threaded'head at one end thereof tosclo se'. that end 'of the pistonbearing said inlet'and outlet'ports;

12; A piumpas defined in claim 9', includingzy.

(a) a flat portion on each of said cams on'that portion thereof comprising the high ,side of such cam. I1

w References Cited in the file r this patent; i UNITED STATES PATENTS 1,606,378 Hajek Oct. 17, 1911 1,866,217 Mayer July 5, 1932 I FOREIGN PATENTS 392,359 France Sept. 22 

1. IN A FLUID INJECTOR PUMP: (A) MEANS FORMING A CYLINDER, (B) A PISTON RECIPROCALLY AND ROTATABLY SUPPORTED IN SAID CYLINDER, (C) SAID PISTON HAVING A RELATIVELY REDUCED DIAMETER CENTRAL SECTION WITH A FLUID PUMPING HEAD PORTION AT ONE SIDE THEREOF AND A DRIVING HEAD AT THE OPPOSITE SIDE, (D) DRIVE MEANS HAVING A SLIDING CONNECTION TO SAID HEAD FOR ROTATING SAID PISTON, (E) SAID PISTON HAVING ONE CAM ON A FACE OF THE PUMPING HEAD FACING SAID REDUCED DIAMETER PORTION AND A SECOND CAM ON A FACE OF THE DRIVING HEAD FACING SAID REDUCED DIAMETER PORTION, (F) A FIRST ACTUATOR ENGAGING SAID FIRST-MENTIONED CAM TO MOVE THE PISTON AS IT ROTATES IN A LONGITUDINAL DIRECTION IN A PRESSURE STROKE, AND (G) A SECOND ACTUATOR ENGAGING SAID SECOND-MENTIONED CAM TO MOVE SAID PISTON AS IT ROTATES IN A LONGITUDINAL DIRECTION IN A SUCTION STROKE. 